Work

Ytterbium lattice clock with systematic uncertainty of 1.3 × 10 −18 and instability at the 10 −19 level

Year: 2026

Type: article

Abstract: We report an optical lattice clock based on 171 Yb atoms with a total systematic uncertainty of 1.3 × 10 − 18 . An in-vacuum buildup cavity was employed to enhance the lattice light power. Differential frequency measurement between two identical clocks facilitates the evaluation of systematic shifts. Synchronous comparison of the two clocks reached a stability level of 2.7 × 10 − 19 in an averaging time of 216 000 s. The blackbody radiation (BBR) shield which is placed in vacuum provides a well-characterized BBR environment, enabling an uncertainty contribution of 8.7 × 10 − 19 from the BBR Stark shift. Lattice light shifts were measured at different lattice depths U , and fitted with a fourth-order polynomial of U . The zero-linear-shift frequency ν zero was determined to be 394 798 260.6(3) MHz. The lattice light shift can be controlled at an uncertainty level of 6.3 × 10 − 19 under typical operating conditions. Other systematic shifts have also been evaluated. The two clocks will be used for remote frequency comparisons between Shanghai and Wuhan.

Source: Metrologia

DOI: 10.1088/1681-7575/aeb809